Theophylline-Induced Left Ventricular Relaxation Disturbance in Magnesium-Deficient Rats: Improvement by K201, a Novel 1,4-Benzothiazepine Derivative.

BACKGROUND: Although magnesium deficiency induces left ventricular dysfunction, it is not known whether both systolic and diastolic functions are altered to the same extent. In this study, we investigated the effects of theophylline on left ventricular function in rats fed a normal diet or a magnesium-deficient diet for 1 month, and determined whether K201, a multi-channel blocker, modulated the effects of theophylline. METHODS: Theophylline was infused at 5 mg/kg/min for 15 min in 6 control rats and 6 magnesium-deficient rats, and hemodynamic measurements were performed. In another 6 magnesium-deficient rats, K201 was infused at 0.1 mg/kg/min for 15 min simultaneously with theophylline. RESULTS: Theophylline induced persistent increases in heart rate, peak positive first derivative of left ventricular pressure (+dP/dt), and a transient increase in left ventricular end-diastolic pressure (LVEDP), but did not affect left ventricular systolic pressure (LVSP) and peak negative first derivative of left ventricular pressure (-dP/dt) in the control rats. In contrast, in the magnesium-deficient rats, there was a persistent decrease in LVSP and a persistent increase in -dP/dt after theophylline infusion, although increases in heart rate, +dP/dt and LVEDP were similar to those in the control rats. When K201 was infused along with theophylline in the magnesium-deficient rats, both the decrease in LVSP and increase in -dP/dt were suppressed. CONCLUSIONS: Theophylline impaired left ventricular function in the magnesium-deficient rats, and this was improved by K201. K201 may provide new insights regarding future strategies for heart failure treatment.

The wound healing response after implantation of a drug-eluting stent is impaired persistently in the long term.

A 70-year-old man underwent stent implantation for right coronary artery (RCA) lesions with a bare metal stent (BMS) and two sirolimus-eluting stents (SES). However, as both the BMS and SES stented sites developed restenosis after 13 months, he underwent target lesion revascularization using directional coronary atherectomy (DCA). On histopathology, the restenosis lesion at the SES-deployed site showed greater inflammation and less re-endothelialization than that at the BMS-deployed site. Three months later, the SES-deployed site developed a second restenosis, in which paclitaxel-eluting stents (PES) were implanted (PES-in-SES), while the BMS-deployed site was restenosis free. Five years later, restenosis was absent in these RCA lesions. However, by optical coherence tomography and/or coronary angioscopy, the PES-in-SES site in the RCA showed poor neointimal coverage over the stent struts and yellowish neointima, suggesting lipid-rich neoatheroma formation, whereas at the BMS site appropriate white neointima formation was observed. Drug-eluting stents still have problems of persistent inflammation, inappropriate neointima formation, and neoatherosclerosis. Although we are now in the era of second generation DESs in which better stent performance would be promising, we should remember that we are obliged to continue to follow-up all patients in whom first generation DESs such as SES or PES have been placed.

Comparison of the performance of zotarolimus- and everolimus-eluting stents by optical coherence tomography and coronary angioscopy.

Overall stent performance should be characterized by geometric luminal gain acquisition, neointimal coverage of the stent struts, and stabilization of the underlying inflammatory neoatheroma. The aim of this study was to compare the performance of zotarolimus-eluting stent (ZES), everolimus-eluting stent (EES) and bare metal stent (BMS) using optical coherence tomography (OCT) and coronary angioscopy. For 36 stented coronary lesions (BMS, 12 lesions; ZES, 11 lesions; EES, 13 lesions) in 27 patients, we calculated neointimal area and uncovered stent strut rate based on OCT findings at 10 months after stent placement. The grades of neointimal coverage and yellow color, both of which were classified from 0 to 3, were also assessed by coronary angioscopy. The plaque area of the ZES lesions was larger than that of the EES lesions (P < 0.05) but smaller than that of the BMS lesions (P < 0.05). The OCT-based uncovered rate of the ZES lesions was less than that of the EES lesions (P < 0.01), but similar to that of the BMS lesions. The stent coverage grade by angioscopy was higher in the ZES lesions than in the EES lesions (P < 0.05), but similar to the BMS lesions. The yellow grade was less in the ZES lesions than in the EES lesions (P < 0.01), but similar to the BMS lesions. ZES might be better than BMS in terms of neointimal thickening, and better than EES in terms of neointimal coverage as well as prevention of neoatheroma formation. ZES may have superior performance compared with EES.

The late-phase inflammatory response after drug-eluting stent implantation.

Recent advances in drug-eluting stent (DES) technology have succeeded in preventing restenosis. In addition to inhibiting smooth muscle cell proliferation, DES greatly inhibits the local inflammatory response in the acute phase after implantation, leading to prevention of restenosis. However, a unique issue in DES implantation is an impairment of reendothelialization, which may result in abnormal wound healing. Consequently, a late-phase inflammatory relapse could appear in the long term after DES implantation. In this study, we measured serum levels of inflammatory markers, including interleukin (IL)-6, IL-8, tumor necrosis factor-α, monocyte chemoattractant protein-1, matrix metalloproteinase-9, and myeloperoxidase, as well as high-sensitivity C-reactive protein at follow-up coronary angiography (mean 9 months) in 54 patients who received DES stenting who did not experience restenosis, and compared them with 51 patients receiving bare-metal stents (BMS) without restenosis. The level of IL-6 was over the measurement threshold (≥2.22 pg/ml) in 12 patients (21 %) in the DES group, but in only 2 patients (4 %) in the BMS group (P = 0.003). IL-8 was significantly higher in the DES group than in the BMS group (4.51 ± 2.40 vs 3.84 ± 1.34 pg/ml, P = 0.015). The levels of other biomarkers were similar between the two groups. DES showed an increase in inflammatory cytokines in the late phase after implantation in comparison with patients who received BMS, suggesting late-stage inflammation. Therefore, the wound-healing response after DES implantation might be different from that after BMS.

[Patient Radiation Dose for Percutaneous Coronary Intervention by Treatment Area: Dosimetry Using DRLs 2020].

PURPOSE: Skin injury in patients due to radiation exposure has been a complication in percutaneous coronary intervention (PCI) for a long time. To the best of our knowledge, there have been no reports comparing radiation dose by treatment area with diagnostic reference levels (DRLs) 2020, although the radiation dose varies by treatment area in PCI. METHODS: In this study, the treatment areas were classified into four segments (i.e., AHA #1-3, AHA #4, AHA #5-10, and AHA #11-15), and each segment was compared with DRLs 2020. This retrospective study included 984 consecutive patients with single-vessel disease and non-chronic total occlusion. PCI was performed on a single device. RESULTS: The median radiation dose was 1640.8 mGy, and the radiation dose for AHA #4 was 2732.0 mGy, which was significantly higher than the other treatment areas (p<0.001). In AHA #4, the radiation dose increased due to the heavy use of the left cranial view, and the patient background contributed to the increased lesion complexity. Therefore, it was challenging to evaluate AHA #4 and the other treatment areas with a uniform DRL value. CONCLUSION: Establishing a subdivided index for each treatment area is crucial if DRLs are used as a reference during procedures and as a guide for dose optimization.

Mobilization of progenitor cells and vessel healing after implantation of SYNERGY in acute coronary syndrome.

This study was aimed to compare the vascular healing process of a SYNERGY stent with that of a PROMUS PREMIER stent in patients with acute coronary syndrome (ACS). In 71 patients with ACS, undergoing coronary stent implantation using the SYNERGY stent (n = 52) or PROMUS PREMIER stent (n = 19), we measured circulating CD34+/CD133+/CD45null cells and CD34+/KDR+ cells and observed vascular healing at the stented sites using optical coherence tomography (OCT) and coronary angioscopy. On the day 7, circulating CD34+/CD133+/CD45null cells increased in SYNERGY group (P < 0.0001), while it did not change in PROMUS group. The CD34+/KDR+ cells also increased in SYNERGY group (P < 0.0001) but less significantly in the PROMUS group (P < 0.05). The OCT-based neointimal thickness (P < 0.0005) and neointimal coverage rate (P < 0.05) at 12 months were greater in SYNERGY group, compared with PROMUS group. The coronary angioscopy-based neointimal coverage grade at 12 months was also greater in SYNERGY group (P < 0.001). In overall patients, the change in CD34+/KDR+ cells on the day 7 correlated with the OCT-based neointimal thickness at 12 months (R = 0.288, P < 0.05). SYNERGY stent seems to have potential advantages over PROMUS PREMIER stent for ACS patients in terms of vascular healing process at the stented sites.

Early effect of lipid-lowering therapy with pitavastatin on regression of coronary atherosclerotic plaque. Comparison with atorvastatin.

BACKGROUND: Virtual histology intravascular ultrasound (VH-IVUS) is used to diagnose coronary plaques and evaluate statin therapy. However, in most cases, quantitative changes in plaques have been evaluated in the chronic stage. We evaluated the quantitative and qualitative early effects of 2 statins on coronary lesions using VH-IVUS. METHODS AND RESULTS: Patients with acute coronary syndrome who underwent emergency percutaneous coronary intervention (PCI) were randomly assigned to receive pitavastatin (n=80; 2 mg/day) or atorvastatin (n=80; 10 mg/day) immediately after PCI. All patients underwent a blood lipid test and VH-IVUS evaluation of non-PCI lesions at admission and after 2-3 weeks of statin administration. After treatment, total cholesterol and low-density lipoprotein-cholesterol (LDL-C) showed significant decreases to similar levels in each group (P<0.001). In the pitavastatin group, the plaque volume index and fibrofatty volume index (FFVI) also decreased significantly. In patients from the pitavastatin group with a dense calcium ratio of < or =10% (n=61), the percentage changes in FFVI and LDL-C were correlated positively (r=0.305, P=0.017), whereas no significant changes were found after treatment in the atorvastatin group. CONCLUSIONS: Fibrofatty composition and plaque volume decreased significantly following treatment with pitavastatin, which suggests that pitavastatin might have a higher affinity for fibrofat compared with atorvastatin.

The different features of angiographic peri-stent contrast staining after implantation of sirolimus-eluting stents.

If we had a case with angiographic peri-stent contrast staining(PSS)s after the first-generation sirolimus-eluting stent, we need a further observation using coronary imaging modalities to evaluate the risk of very late stent thrombosis due to PSSs and to continue or to resume the dual antiplatelet therapy if necessary.

Which has the stronger impact on coronary artery disease, eicosapentaenoic acid or docosahexaenoic acid?

It has been suggested that n-3 polyunsaturated fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), protect against cardiovascular diseases, and EPA/arachidonic acid (AA) and DHA/AA ratios in serum are potential risk markers for coronary artery disease (CAD). The purpose of this study was to clarify the clinical significance of the difference in the EPA/AA ratio and the DHA/AA ratio in patients with CAD. In 369 patients with confirmed or suspected CAD who underwent diagnostic coronary angiography, we measured serum levels of EPA, DHA and AA and calculated the EPA/AA and DHA/AA ratios. The EPA/AA ratio was significantly lower in patients with acute coronary syndrome (ACS) than in patients with chronic CAD or chest pain syndrome (0.27±0.19 vs. 0.44±0.20, respectively; P<0.01), whereas the DHA/AA ratio was similar in the two groups (0.78±0.27 vs. 0.79±0.37). Multiple logistic regression analyses using various biomarkers related to coronary risk discriminated ACS from other disease entities and demonstrated that the EPA/AA ratio (odds ratio: 0.0012, 95% confidence interval: 0.00-0.16, P<0.01) but not the DHA/AA ratio (odds ratio: 1.05, 95% confidence interval: 0.98-1.12) was a significant independent predictive factor. Our findings suggest that the EPA/AA ratio might be more closely associated with the pathophysiology of CAD, especially with that of ACS, than the DHA/AA ratio. Our findings suggest that interventions with EPA agents or supplemental EPA intake, compared with DHA agents or supplemental DHA, may confer greater benefit for plaque stabilization to prevent the onset of ACS in patients with CAD.

Clinical significance of non-slip element balloon angioplasty for patients of coronary artery disease: a preliminary report.

BACKGROUND: Recent advances in drug-eluting stent (DES) technology have succeeded in reducing restenosis. However, the use of DES is reportedly equivalent to bare metal stents in terms of long-term survival. In addition, stent materials represent foreign bodies, which if possible should not ideally be left within the patient. On these bases, an investigation was performed into the feasibility of a new approach, 'stentless' percutaneous coronary intervention (PCI), using a Lacrosse(®) non-slip element (NSE) balloon (Goodman Co., Ltd., Nagoya, Japan). METHODS AND RESULTS: In our 'stentless' approach, the NSE balloon is used for target lesion dilation in patients with low risk factors and simple target lesions. No stenting was performed once an optimal dilatation result was achieved, as evaluated by intravascular ultrasound (IVUS). In a total of 340 lesions in 304 patients, in whom the follow-up study was completed, the 'stentless' PCI by NSE balloon alone was achieved in 52 lesions (15%). Target lesion revascularization (TLR) was performed for 5 (9.6%) of the 52 'stentless' lesions. In the comparison between the 52 'stentless' lesions and the 31 DES lesions selected under the statistical matching of the patient profiles and baseline lesion characteristics, the TLR rate (9.6% vs 6.5%, p=0.616) and late lumen loss (0.52±0.26 mm vs 0.48±0.21 mm, p=0.347) were similar. In the 52 'stentless' lesions, IVUS parameters such as vessel area, minimal lumen area, and plaque area at both before and immediately after PCI were similar between the 5 TLR lesions and the 47 non TLR lesions. CONCLUSIONS: It is believed that the 'stentless' approach is applicable even in the DES era.

Clinical features of spontaneous coronary artery dissection.

BACKGROUND: Spontaneous coronary artery dissection (SCAD) is an infrequent but increasingly recognized cause of acute coronary syndrome (ACS). Previous case reports demonstrated that this condition occurs in young females with a low atherosclerotic risk factor burden and may be associated with peripartum or postpartum status. The purpose of this study was to review patients with angiographically confirmed SCAD to provide additional insight into the diagnosis and treatment of this condition. METHODS AND RESULTS: We screened medical records of all patients with ACS from March 2001 to November 2012. From these patients, we selected patients with SCAD based on coronary angiographic review. Of a total of 1159 ACS patients, 10 patients (0.86%) were diagnosed with SCAD. The mean age of these patients was 46 years, and 9 were female. ST-elevation myocardial infarction (STEMI) was observed in 9 patients and 5 patients had no coronary risk factors. One patient was treated conservatively with medication alone and 3 patients underwent thrombectomy. Balloon angioplasty was performed in 2 patients, and a bare metal stent was placed in one of these patients later. In the remaining 4 patients, bare metal stents were implanted emergently. Follow-up coronary angiography showed appropriate repair of SCAD in all 10 patients. CONCLUSIONS: In our experience, the clinical features of SCAD appear to be similar to those reported previously. SCAD appears to be rare, but it should be considered in ACS patients, especially in younger females.

Evaluation of serial changes in tissue characteristics during statin-induced plaque regression using virtual histology-intravascular ultrasound studies.

Treatment of all coronary arteries is important to improve the prognosis of acute coronary syndrome after early reperfusion of the culprit lesion. Early statin treatment has been reported to cause regression of plaques away from the site of the culprit lesion in patients with acute coronary syndrome. However, the precise mechanism of coronary plaque regression is not well understood. We studied the effects of statins on the regression of coronary plaques away from the culprit lesions in 120 patients with acute coronary syndrome. We used virtual histology-intravascular ultrasound studies to evaluate nonpercutaneous coronary intervention lesions at admission and short-term (2 to 3 weeks) and medium-term (8 to 10 months) follow-up. According to the medium-term evaluation findings, the subjects were divided into 2 groups: a plaque regression group (n = 94) and a plaque progression group (n = 26). In the regression group, the fibrofatty component had decreased at the short-term (-20.0% vs baseline) and had decreased further at the medium-term (-26.7%) evaluations. The fibrous component had also decreased at the short-term (-5.1%) and medium-term (-8.5%) evaluations. In contrast, the necrotic core component showed a tendency to increase in the short term (+12.5%) but then decreased at the medium-term evaluation (-6.3%). In the progression group, the fibrofatty and fibrous components had increased at the short-term (+37.5%, +11.3%) and medium-term (+50.5%, +13.2%) evaluations; however, the necrotic core had decreased at the short-term (-19.0%) and medium-term (-23.8%) evaluations. In conclusion, regarding the course of coronary plaque regression by statin therapy, the plaques began to reduce the volume of fibrofatty and fibrous components in the early phase, associated with a transiently increased necrotic core component. Furthermore, even in the case of plaque progression, statins caused a reduction in the necrotic core.

Late-phase inflammatory response as a feature of in-stent restenosis after drug-eluting stent implantation.

OBJECTIVES: The aim of this study was to compare pathological features among in-stent restenosis lesions after drug-eluting stent (DES) placement, those after bare metal stent (BMS) placement, and de-novo atherosclerotic lesions. BACKGROUND: Restenosis after stenting is an over-reaction of the wound-healing response after vascular injury, which is characterized by a sequence of inflammation, granulation, extracellular matrix remodeling, and smooth muscle cell proliferation and migration. Recent advances in DES technology could considerably succeed in inhibiting this sequence of events. Thus, we hypothesized that the mechanism of in-stent restenosis after DES stenting might be different from that after BMS stenting as well as atherosclerosis. METHODS: Tissues obtained by directional atherectomy (DES: seven specimens, BMS: 17 specimens, and de-novo: 15 specimens) were immunostained for T lymphocytes (CD45), macrophages (CD68), smooth muscle cells (α-smooth muscle actin), endothelial cells (von Willebrand factor), and activated platelets (P-selectin). RESULTS: The accumulation of T lymphocytes tended to increase and that of macrophages increased significantly in the DES lesions compared with BMS lesions. No significant differences were observed for the other parameters evaluated. CONCLUSION: Pathological features of restenotic tissues after DES implantation showed a stronger inflammatory response compared with those after BMS implantation. Thus, the mechanism of restenosis after DES implantation may be different from that observed after BMS implantation.

Pathological features of in-stent restenosis after sirolimus-eluting stent versus bare metal stent placement.

A 70-year-old man developed diffuse restenosis in the right coronary artery, in which a bare metal stent (BMS) and two sirolimus-eluting stents (SES) were deployed sequentially. He underwent directional coronary atherectomy (DCA) for in-stent restenosis (ISR) lesions 13 months after both BMS and SES stenting. Further 4 months later, that is, 17 months after stent implantation, however, ISR recurred just at the SES site alone. Then we performed second DCA for the ISR lesion at SES site. The tissue materials obtained from debulking were compared histologically. In the first DCA specimen, accumulation of inflammatory cells such as T lymphocytes and macrophages was observed densely in ISR lesions at SES site but not in those at BMS site, and endothelial coverage was absent in ISR lesions at SES site but present in those at BMS site. In the second DCA specimen, ISR lesions at SES site showed less inflammatory cells, compared with first DCA specimen. ISR lesions after drug-eluting stenting showed persistent signs of delayed or incomplete wound healing and relapsed inflammation, compared with BMS. Thus, the mechanism of restenosis after drug-eluting stenting may be different from that after BMS placement.

[Right coronary artery to left ventricle fistula associated with three-vessel coronary artery disease: a case report].

Right coronary artery to left ventricle fistula is a rare type of coronary artery fistula among congenital coronary artery anomalies. Most patients exhibit no symptoms and some experience chest pain. Coronary angiography sometimes detects the presence of coronary artery fistula, but not coronary arteriosclerosis. A 76-year-old man with unstable angina was admitted because he did not respond to drug therapy. Coronary angiography showed three-vessel coronary artery disease and the contrast agent entered the left ventricle from the terminal of the right coronary artery during diastole. Multidetector-row computer tomography showed similar findings. The patient subsequently underwent coronary artery bypass grafting and obliteration of the coronary artery fistula. The chest pain was relieved and he is now in good condition.